Formula given acceleration and distance

1. The problem statement, all variables and given/known data
An object is pushed from rest across a sheet of ice, accelerating at 5.0 m/s over a distance of 80 cm. The object then slides at a constant speed for 4.0 s until it reaches a rough section that causes the object to stop in 2.5 s. (Assume 2 significant digits.)
(a) What is the speed of the object when it reaches the rough section?
(b) At what rate does it slow down once it reaches the rough section?
(c) What is the total distance that the object slides?

Can anyone tell me the formula I need to solve this question? Thanks in advance.